Smelting method for improving sulfur dispersion of medium-carbon sulfur-containing steel

A smelting method and sulfur-containing steel technology, which is applied in the field of iron and steel smelting, can solve the problems of deterioration of the comprehensive mechanical properties of steel and the easy deformation of sulfide, and achieve the effects of improving the form of sulfide, improving the purity of molten steel, and simplifying the process flow

Active Publication Date: 2021-08-20
DONGBEI SPECIAL STEEL GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] Based on this, it is necessary to solve the problem that the sulfides of medium-carbon sulfur-containing steel smelted by traditional methods are extremely easy to deform, and they are easy to extend along the rolling direction during the rolling process, forming long strips of sulfides, which significantly deteriorate the comprehensive mechanical properties of the steel, and provide A smelting method for improving sulfur dispersion of medium-carbon sulfur-containing steel

Method used

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  • Smelting method for improving sulfur dispersion of medium-carbon sulfur-containing steel

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Embodiment 1

[0044] In this embodiment, medium-carbon sulfur-containing steel is produced by using the converter primary refining-LF refining-RH vacuum smelting-continuous casting process, and the composition requirements of the steel are C: 0.40-0.44%, Si: 0.20-0.30%, and Mn: 0.50-0.60 %, S: 0.012-0.030%, P≤0.020%, Cr: 0.90-1.10%, Mo: 0.10-0.20%, H≤2.0ppm%, O≤20ppm.

[0045] Converter or electric furnace primary refining:

[0046] Use electric furnace or converter to smelt raw materials into primary molten steel. The total amount of molten steel for tapping is controlled at 110t, and the tapping temperature of molten steel is 1630°C; when the tapping amount is about 25t, 950kg of silicon-manganese alloy is added. After increasing to 55t, add 110kg of aluminum-based deoxidizer. When the tapping amount reaches 100t, add 700kg of pre-melted refining slag and 350kg of lime with the steel flow. The steel retention operation is carried out in the later stage of tapping in the electric furnace ...

Embodiment 2

[0058] In this embodiment, medium-carbon sulfur-containing steel is produced by using the converter primary refining-LF refining-RH vacuum smelting-continuous casting process. The composition requirements of the steel are C: 0.38-0.42%, Si: 0.30-0.45%, and Mn: 0.60-0.80 %, S: 0.035-0.055%, P≤0.015%, Cr: 1.00-1.25%, Mo: 0.15-0.30%, H≤2.0ppm%, O≤20ppm.

[0059] Converter or electric furnace primary refining:

[0060]Use electric furnace or converter to smelt raw materials into primary molten steel. The total amount of molten steel for tapping is controlled at 100t, and the tapping temperature of molten steel is 1640°C; when the tapping amount is about 20t, add 820kg of silicon-manganese alloy. After increasing to 50t, add 105kg of aluminum-based deoxidizer. When the tapping amount reaches 95t, add 650kg of pre-melted refining slag and 350kg of lime with the steel flow. The steel retention operation is carried out in the later stage of tapping in the electric furnace or converte...

Embodiment 3

[0072] In this embodiment, medium-carbon sulfur-containing steel is produced by using the process route of primary smelting in converter-LF refining-RH vacuum smelting-continuous casting, and the composition requirements of the steel are C: 0.50-0.60%, Si: 0.20-0.35%, and Mn: 0.40-0.60 %, S: 0.055-0.075%, P≤0.025%, Cr: 1.10-1.30%, Mo: 0.20-0.45%, H≤2.0ppm%, O≤20ppm.

[0073] Converter or electric furnace primary refining:

[0074] Use electric furnace or converter to smelt raw materials into primary molten steel. The total amount of molten steel for tapping is controlled at 115t, and the tapping temperature of molten steel is 1620°C; when the tapping amount is about 30t, 900kg of silicon-manganese alloy is added. After increasing to 60t, add 120kg of aluminum-based deoxidizer. When the tapping amount reaches 105t, add 600kg of pre-melted refining slag and 350kg of lime along with the steel flow. The steel retention operation is carried out in the later stage of tapping of the...

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Abstract

The invention relates to a smelting method for improving sulfur dispersion of medium-carbon sulfur-containing steel. The smelting method comprises the following steps that in the primary smelting process of a converter, composite deoxidation is carried out by adopting silicon-manganese alloy and aluminum, in the refining process, high-alkalinity slag is formed in molten steel by utilizing pre-melting type refining slag and lime, and then precipitation deoxidation is carried out by adopting an aluminum wire and diffusion deoxidation is carried out by adopting carbon powder and aluminum shots; the content of Al is controlled in the LF refining process, silica is added into molten steel at an LF off-station for slag changing operation, and high-alkalinity slag is adjusted into low-alkalinity slag, so that the yield of a sulfur element is increased; and before RH vacuum smelting, a calcium line is adopted for calcium treatment, so that fine dispersed Al2O3 is denatured into calcium aluminate (Al2O3-CaO), and the calcium aluminate serves as a nucleation center for sulfide precipitation. According to the method, the yield of the sulfur element can be increased, the purity of molten steel is obviously improved, the form of sulfide is improved, the sulfide is well dispersed, and the method has the advantages of being simple in technological process, easy to operate on site, low in production cost and the like.

Description

technical field [0001] The invention relates to the technical field of iron and steel smelting, in particular to a smelting method for improving the dispersion of sulfur in medium-carbon sulfur-containing steel. This method can improve the distribution of sulfides in medium-carbon sulfur-containing steel, reduce the proportion of long-striped sulfides, and make the sulfides dispersed and distributed. The fine series of A-type inclusions is ≤ 2.0 and the thick series is ≤ 1.5. The invention has the advantages of simple technological process, easy on-site operation, low production cost and the like. Background technique [0002] Adding a certain amount of sulfur to steel can improve the cutting performance of steel by using sulfide, especially in crankshaft steel for automobiles. Automobile crankshaft steel generally uses non-quenched and tempered steel, which is a medium-carbon sulfur-containing steel, containing a certain amount of sulfur, generally 0.020-0.050%. However, ...

Claims

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Application Information

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IPC IPC(8): C21C7/06C21C7/00C21C7/076C21C7/10C21C7/072C21C5/28C21C5/52C22C33/06C22C38/02C22C38/04C22C38/22
CPCC21C7/06C21C7/0006C21C7/0068C21C7/0037C21C7/0025C21C7/076C21C7/0056C21C7/10C21C7/072C21C5/28C21C5/52C22C33/06C21C2007/0093C22C38/02C22C38/04C22C38/22Y02P10/20
Inventor 刘建周伟基张志兴林立民毕胜姜盛鑫陈修君冯荣鹏何金泽刘艳林王金国杨薇孔美玲
Owner DONGBEI SPECIAL STEEL GROUP
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